Parabolic golf club head

ABSTRACT

An iron type golf club head having a face with a parabolic cross-sectional shape of the face from the heel to the toe of the head.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to golf club heads.

2. Description of the Related Art

Golf clubs are used in golfing to hit the golf ball, and typically fall into three categories: 1) woods, originally with wooden heads, used to propel the ball for long distances; 2) irons, originally with metal heads with varying degrees of loft, particularly used for somewhat shorter shots as the greens are approached, and 3) putters, for propelling the ball for short distances with extreme accuracy, such as on a putting green itself, and designed to push and roll the ball rather than to hit it up into the air.

Each golf club head has one face which contacts the ball during the stroke. Clubs may have two striking faces, as long as they are identical and symmetrical (some putters and chippers are designed in this fashion, and may be used by left or righthanded players).

The face of the head of the golf club (clubface) is structured to have a particular loft (the angle between a vertical plane and the clubface when the club is at rest), which determines the upward trajectory of the ball. Grooves on the clubface impart a “backspin” on the ball, that when combined with the rebounding effect of the ball, give it lift. Typically, the greater the loft, the higher and shorter the resulting ball trajectory. The typical lofts for irons range from 16 to 48 degrees.

Irons are mainly produced by two processes, casting and forging. Cast irons are produced by casting molten metal in a pre-shaped cast. Forged irons are heated and beaten into the desired shape. Cast irons provide the user with less feel, but are less difficult to hit consistently, and are therefore preferred by the higher handicap golfer. The different types of irons differ in their feel and forgiveness to a user. Most modern golf club heads, particularly of irons, are cast through a process known as investment casting. This process allows manufacturers to redistribute the weight into the perimeter of the club, known as perimeter weighting, which helps to increase the accuracy of misshit shots

Inexperienced golfers and golfers who have not refined their use of irons, often have difficulty hitting the ball and directing the trajectory of the golf ball with irons, which are primarily designed for moving the ball relatively long distances and not for extremely accurate ball placement. Iron heads are typically solid with a flat clubface. Irons are typically either have a hollowed out back (cavity back) or have a smooth back (muscle back). The latter designs are also called ‘blades’ for their low amounts of offset, thin toplines and thin soles, and are generally more difficult to use to hit a golf ball.

A wide variety of attempts have been made to provide an iron type golf club that relieves the problems associated with non-perfect or off-center hits of the ball. For example, the patent of Hutin et al. (U.S. Pat. No. 5,800,282) provides a set of golf clubs having a vibration damping plaque comprising a perimeter weighted element as well as a hosel feature.

A number of patents provide areas of variable curvature on the face of the golf club head. The patent of Gebauer et al. (U.S. Pat. No. 4,508,349) provides a golf club head that has a curved surface, and in particular has a central bulge and accentuated roll (convex) portion separated from upper and lower flat portions by broad grooves. The patent of Werner et al. (U.S. Pat. No. 6,139,445) has a variety of angled designs, such as a lower convex curved portion for irons (FIG. 6), but specifically does not have any concave curvature.

It is therefore an object of the invention to provide an iron type golf club head, particularly for an iron, that has a form that increases the likelihood of accurate hitting of a golf ball.

Other objects and advantages will be more fully apparent from the following disclosure and appended claims.

SUMMARY OF THE INVENTION

The invention herein is an iron type golf club head having a face with a parabolic cross-sectional shape of the face as viewed from the heel to the toe of the head.

Other objects and features of the inventions will be more fully apparent from the following disclosure and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear perspective view of a prior art iron type golf club head.

FIG. 2 is a diagram of a parabola.

FIG. 3 is a rear perspective view of an iron type golf club head of the invention.

FIG. 4 is a rear perspective view of a second style of iron type golf club head modified according to the invention.

FIG. 5 is a rear perspective view of a third style of iron type golf club head modified according to the invention.

FIG. 6 is a front perspective view of the golf club head of FIG. 5.

FIG. 7 is a top plan view of a fourth (blade) style of iron type golf club head modified according to the invention.

FIG. 8 is a heel end elevational view of the golf club head of FIG. 7 in which the face is oriented at an angle as might be used in play.

FIG. 9 is a side elevational view from the toe end of the golf club head of the invention in which the face is oriented horizontally.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS THEREOF

The present invention is an iron type golf club head for hitting a golf ball. As shown in FIGS. 3-10, the golf club head 10 of the invention has a modified front striking face 20 for impacting a ball and a rear surface 22 opposite the front striking face 20. Although the preferred iron type golf club head of the invention is a “blade” type as known in the art, whether or not the head is a blade or has a hollowed out rear surface 22 or other rear features, the front striking face 20 is very slightly bowed inward toward the rear surface in a parabolic shape as discussed below. This is in clear contrast to the flattened striking face shape of prior iron type golf club heads 25, an example of which is shown in FIG. 1, and which is shown by dashed line in FIGS. 4-7.

As used herein, the word “toe” 24 refers to the outermost portion of the end of the head 10 that is distal from the handle 28, while “heel” 26 refers to the innermost portion of the end of the head 10 that is proximal to the handle 28.

As used herein, the term “parabolic” is used in its normal sense, as a plane curve generated by point moving so that its distance from a fixed point P is equal to its distance from a fixed line F. The parabolic form of the front striking face 20 of the golf club head 10 of the invention is the form of the flatter central area C of a parabola that is symmetric about a line L drawn perpendicular to the fixed line F as shown, with an example of the parabolic curve that may be used in the modified front striking face of the invention being shown in FIG. 2. The position of imaginary line L on the golf club is preferably centered between toe 24 and heel 26 so that the parabolic face has its lowest point mid-way between toe 24 and heel 26, however, it is within the scope of the invention herein to move this lowest point to either side of the middle of the face, so that the parabolic face is slightly shifted toward the toe or toward the heel.

The front striking face 20 of the iron type golf club head 10 of the invention has the following features. As is known in the art, when the golf club of the invention is oriented for contacting a golf ball, the overall plane of the front striking face 20 (as shown by a plane tangent to the central portion of the club face) forms an angle with a vertical line, known as the loft. Golf clubs with which the modification of the invention may be used include those having any loft as is known in the art of iron type golf club heads.

The front striking face 20 of the golf club head 10 of the invention is slightly concave with a slight parabolic concavity 30 being formed between the heel 26 and the toe 28 of the golf club head, as shown in FIGS. 3-8 and 10. This slight concavity 30 is defined herein a preferably at least about ⅛ inch at its greatest depth (with a range of about ⅛-¼ inch). Thus, as used herein the term “slight parabolic concavity” is a concavity having a maximum depression (as compared to a flat face extending between the toe and heel) of between about ⅛ and ¼ inch. A substantially greater curvature would increase the risk of causing mis-direction of a ball that had been hit with such a golf club head.

When the head 10 of the invention viewed from the toe end 24 of the front striking face 20, there is no curvature (FIG. 9). In other words the amount of concavity 30 (deviation from a flat face) is the same at any particular distance from the toe end 24 so that when the golf club head is viewed from either the toe or the heel, the face 20 is flat and not parabolic in shape. For example, at 1 cm from the toe end at any place across the face of a particular golf club head, the amount of concavity would be the same, for example, 1/16 inch. Thus, the parabolic form is such that at any cross section showing the front striking face and taken from the toe 24 to the heel 26 the shape of the front striking face 20 is the same downward parabola, dipping downward from the toe and back up to the heel of the face as shown in FIG. 10.

While the invention has been described with reference to specific embodiments, it will be appreciated that numerous variations, modifications, and embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of the invention. 

1. An iron type golf club head for hitting a golf ball, including a club head body having a heel, a toe and a front striking face, wherein the front striking face has a slight parabolic concavity on the front striking face between the heel and toe.
 2. The iron type golf club head according to claim 1, wherein the slight parabolic concavity is about ⅛ inch in depth centrally between the toe and heel.
 3. The iron type gold club head according to claim 1, wherein the golf club head is a blade type head. 